1. Field
This invention relates to exercise equipment and, more specifically, to bars for exercising the upper body, particularly the torso, such as in bending and twisting exercises.
2. State of the Art
Exercise equipment is a crowded art. Exercise machines for simulating numerous competitive and athletic activities are marketed. In addition, numerous patents abound from the 19th and 20th centuries for exercise apparatus. Free weights, such as barbells and dumbbells, are produced by numerous manufacturers. In addition, numerous exercise stations for developing specific muscle groups exist.
Yokes for cattle, and for persons carrying loads have been known for hundreds of years, and probably for millennia. In exercise equipment, yokes and bars are used for various purposes. Barbells use a common bar, typically cylindrical or annular in cross section. Exercise machines use various bars and levers to position resistance properly with respect to the body.
U.S. Pat. Nos. 3,989,241 (Ourgant 1976), 4,072,309 (Wilson 1978), 4,200,280 (Goodwin 1980), 4,358,108 (Voris 1982) and 4,744,559 (Mahnke et al. 1988) disclose bars which can be gripped by the hands of a user and brought near the neck and shoulders. Most are associated with exercise machines. A commercialized bar is advertised as the EXERSTIK.TM.. It is a bar for use in exercises and has a depression to fit over the neck. Consumer publications and trade magazines like Club Industry advertise various bars and machines periodically for exercising at home or spas.
Small, transportable exercise equipment has its adherents likewise. Exercise equipment having wheels, handles, ropes, bands and other structures fit in suitcases for the traveler.
Athletes have long used either a barbell bar or a wooden shaft, such as a broomstick, for exercising the torso in bending and twisting exercises. In a torso-twisting exercise, also called trunk twists, a user places a bar or rod over the shoulders behind the neck. In a standing position, a user wraps a hand around each opposite end of the bar. Holding on to the bar assures that shoulder, chest and back muscles close to the shoulders stay in the same relative positions. The upper torso becomes a rigid body with respect to the waist. The bar also keeps body weight high and at maximum diameter about an axis of rotation. If a barbell is used, the angular momentum of the bar as it rotates with the body of a user must be overcome to change the direction of rotation. The additional moment of inertia of the heavy, long bar can substantially influence the rate of energy burned by a user as well as the force required to change direction of twist in a specified time.
A bar for torso twists can also be used to maintain posture and balance for other exercises. Sometimes a bar can be used for exercising one member of the body against another in isometric relation.
Bars have drawbacks. A bar behind the neck puts most of the muscle groups in the upper body out of their natural position. Biceps, triceps, latissimus dorsi, trapezius, upper pectorals and shoulders are all moved to a non-neutral position, a stressed non-equilibrium position. Likewise, the neck is moved forward to an unnatural position. Because various muscles are moved from their natural unstressed positions, their tendency to return to a relaxed neutral position puts force on the bar. Force on the bar also tends to create soreness in the upper back where the bar rests across the shoulder, and against the neck where muscles are compressed between the hard bar and the internal vertebrae.
Discomfort of a user is a disincentive to continue to exercise. An uncomfortable user will cease exercising entirely in some cases. In many cases, a user will cut short a daily regimen which causes continued discomfort.
Muscles which are not in their relaxed equilibrium position are said to not be neutralized. Non-neutralized
muscle groups are being exercised in an isometric fashion. Muscles can become sore. Also, muscles which are extended more may become sore or are improperly developed in relationship to other muscle groups. Much of exercise technology addresses balanced building of all muscle groups.
For torso twists, a bar is needed which allows all upper body muscle groups to be relaxed in a neutral position. Thus, muscles are only stressed due to the exercise, not due to the mere presence of the bar. The bar needs to be comfortable over the neck and shoulders. The bar should allow various hand positions between shoulder width and full radial extension. The bar should be adaptable for use by users of different sizes and ages.
A bar which is portable has added convenience, a factor of commercial importance. The bar preferably can be varied in weight between the weight of a broomstick and the weight of a barbell bar.
The bar should have the capability to add a large moment of inertia. Large moments of inertia are achieved by additional mass and additional distance between the mass and the center of rotation. The bar should be useful for a variety of exercises in addition to torso twists so that a user can maximize the utility of an investment in the bar as an exercise apparatus. An exercise device which can exercise different muscle groups by slight changes or simply by different exercise methods is more desirable to many users.